Supercritical carbon dioxide (SCO₂) is widely used in many fields of energy and power engineering, such as nuclear reactors, solar thermal power generation systems, and refrigeration systems. In practical applications, SCO₂ undergoes a cooling process significantly when it is cooled near the pseudo–critical point. Because of the drastic variations in thermo–physical properties, the heat transfer characteristics fluctuate, affecting the heat exchange and overall cycle performance. This paper summarizes extensive experiments and numerical simulations on the cooling process of SCO₂ in various application scenarios. The effects of various working conditions, such as mass flow, working pressure, pipe diameter, flow direction, and channel shapes, are reviewed. The applicability and computational results using different numerical methods under different working conditions are also summarized. Furthermore, empirical correlations obtained in experiments at different conditions are included. The present review can provide a helpful guideline for the design of effective cooling systems or condensers so that the accuracy of the design and efficiency of the system can be improved.

In view of the Three North areas existing wind power absorption and environment pollution problems, the previous scholars have improved the wind abandon problem by adding electrothermal coupling equipment or optimizing power grid operation. In this paper, an electrothermal integrated energy system including heat pump and thermal storage units was proposed. The scheduling model was based on the load data and the output characteristics of power units, each power unit capacity was programmed without constraints, and the proposed scheduling model was compared with the traditional combined heat and power scheduling model. Results showed that the investment and pollutant discharge of the system was reduced respectively. Wind power was fully absorbed. Compared with the traditional thermal power unit, the proportion of the output was significantly decreased by the proposed model. The proposed system could provide a new prospect for wind power absorption and environment protection.